Conventional lamp sets are quite bulky and often need a higher socket coupled with a bowl-shaped lamp shade formed at a smaller depth. When used for a prolonged period of time a higher temperature is generated that could be hazardous. Moreover, when the conventional lamp sets are configured in multiple numbers, multiple images are generated and overlapped, they also are called ghost images. In addition, the conventional lamp sets often produce flicker illumination that easily causes fatigue of users' eyes and results in ill effect to users' vision.
Light emitting diode (LED), compared with the conventional lamp sets, adopts a different approach to receive power supply and generate light. Hence the lighting fixtures for LED cannot adopt the conventional design and require a new approach. Due to smaller size and higher illumination of the LED, the light scatters in all directions through the conventional lamp shade that could cause discomfort to users' eyes. Many methods have been proposed to remedy the aforesaid problems, such as increasing the number or illumination of the LEDs. While illumination is increased, power consumption is reduced and temperature is lowered, the problem of multiple images becomes even more severe due to light scattering. This problem must be resolved by taking into account of light refraction and reflection, and design of the lamp shade.